Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
Add filters

Language
Year range
1.
Viruses ; 14(9)2022 09 13.
Article in English | MEDLINE | ID: covidwho-2033143

ABSTRACT

In late November 2021, the World Health Organization declared the SARS-CoV-2 lineage B.1.1.529 the fifth variant of concern, Omicron. This variant has acquired over 30 mutations in the spike protein (with 15 in the receptor-binding domain), raising concerns that Omicron could evade naturally acquired and vaccine-derived immunity. We utilized an authentic virus, multicycle neutralisation assay to demonstrate that sera collected one, three, and six months post-two doses of Pfizer-BioNTech BNT162b2 had a limited ability to neutralise SARS-CoV-2. However, four weeks after a third dose, neutralising antibody titres were boosted. Despite this increase, neutralising antibody titres were reduced fourfold for Omicron compared to lineage A.2.2 SARS-CoV-2.


Subject(s)
COVID-19 , Vaccines , Antibodies, Neutralizing , Antibodies, Viral , BNT162 Vaccine , COVID-19/prevention & control , COVID-19 Vaccines , Humans , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Viral Envelope Proteins/genetics
2.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-296535

ABSTRACT

In late November 2021, the World Health Organization declared the SARS-CoV-2 lineage B.1.1.529 the fifth variant of concern, Omicron. This variant has acquired 15 mutations in the receptor binding domain of the spike protein, raising concerns that Omicron could evade naturally acquired and vaccine-derived immunity. We utilized an authentic virus, multicycle neutralisation assay to demonstrate that sera collected 1, 3, and 6 months post-two doses of Pfizer-BioNTech BNT162b2 has a limited ability to neutralise SARS-CoV-2. However, four weeks after a third dose, neutralizing antibody titres are boosted. Despite this increase, neutralising antibody titres are reduced 4-fold for Omicron compared to lineage A.2.2 SARS-CoV-2.

3.
Clin Infect Dis ; 73(9): e2952-e2959, 2021 11 02.
Article in English | MEDLINE | ID: covidwho-1501018

ABSTRACT

BACKGROUND: The detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA by reverse-transcription polymerase chain reaction (PCR) does not necessarily indicate shedding of infective virions. There are limited data on the correlation between the isolation of SARS-CoV-2, which likely indicates infectivity, and PCR. METHODS: A total of 195 patients with Coronavirus disease 2019 were tested (outpatients, n = 178; inpatients, n = 12; and critically unwell patients admitted to the intensive care unit [ICU] patients, n = 5). SARS-CoV-2 PCR-positive samples were cultured in Vero C1008 cells and inspected daily for cytopathic effect (CPE). SARS-CoV-2-induced CPE was confirmed by PCR of culture supernatant. Where no CPE was observed, PCR was performed on day 4 to confirm absence of virus replication. The cycle thresholds (Cts) of the day 4 PCR (Ctculture) and the PCR of the original clinical sample (Ctsample) were compared, and positive cultures were defined where Ctsample - Ctculture was ≥3. RESULTS: Of 234 samples collected, 228 (97%) were from the upper respiratory tract. SARS-CoV-2 was isolated from 56 (24%), including in 28 of 181 (15%), 19 of 42 (45%), and 9 of 11 samples (82%) collected from outpatients, inpatients, and ICU patients, respectively. All 56 samples had Ctsample ≤32; CPE was observed in 46 (20%). The mean duration from symptom onset to culture positivity was 4.5 days (range, 0-18). SARS-CoV-2 was significantly more likely to be isolated from samples collected from inpatients (P < .001) and ICU patients (P < .0001) compared with outpatients, and in samples with lower Ctsample. CONCLUSIONS: SARS-CoV-2 culture may be used as a surrogate marker for infectivity and inform de-isolation protocols.


Subject(s)
COVID-19 , Animals , Chlorocebus aethiops , Critical Care , Humans , Immunologic Tests , SARS-CoV-2 , Vero Cells
4.
Virus Evol ; 6(1): veaa027, 2020 Jan.
Article in English | MEDLINE | ID: covidwho-1388022

ABSTRACT

The SARS-CoV-2 epidemic has rapidly spread outside China with major outbreaks occurring in Italy, South Korea, and Iran. Phylogenetic analyses of whole-genome sequencing data identified a distinct SARS-CoV-2 clade linked to travellers returning from Iran to Australia and New Zealand. This study highlights potential viral diversity driving the epidemic in Iran, and underscores the power of rapid genome sequencing and public data sharing to improve the detection and management of emerging infectious diseases.

SELECTION OF CITATIONS
SEARCH DETAIL